Electrochemical pretreatment of a glassy carbon electrode for sensitive determination of epinephrine†

In this study, a novel pretreatment of a glassy carbon electrode was conducted via cyclic voltammetry (CV), successfully fabricating an activated glassy carbon electrode (AGCE). A simple two-step electrochemical pretreatment method was established. During the first stage, anodic oxidation pretreatment was achieved by potentiometric scanning across a wide potential range and at a high anodic potential. The reduction stage was subsequently executed through potentiometric scanning within a narrow potential window at a reduced anodic potential. Field atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS), and CV were utilized to characterize the morphology and properties of the pretreated electrodes. The results indicate that the AGCE possesses a rough surface and exhibits increased oxidation peak currents and decreased overpotential during epinephrine (EP) oxidation. Quantitative determination of EP was performed via linear sweep voltammetry (LSV), revealing that the AGCE can effectively recognize EP in a wide range of interferences, spanning a broad linear range of 0.1–8, 8–100, and 100–700 μM. The detection limit (DL) was 0.032 μM. The AGCE exhibited favorable selectivity, stability, and reproducibility in the detection of EP.